СРОЧНО!!!!!! Помогите

$8x+8y-3\frac{2}{5} =8(x+y)-3,4$

x + y = 1,25

8 * 1,25 - 3,4 = 10 - 3,4 = 6,6

$(0.4x-\frac{2}{5}y)*9.8=(0.4x-0.4y)*9.8=0.4(x-y)*9.8=3.92(x-y)$

x - y = 3.5

3.92 * 3.5 = 13,72

$12\frac{4}{5}x*1.25y=12.8x*1.25y=16xy$

x * y = 5/8

$16*\frac{5}{8} =10$

$(\frac{3}{5}x+0.6y)*2.25=(0.6x+0.6y)*2.25=0.6(x+y)*2.25=1.35(x+y)$

$x+y=2\frac{2}{9} \\ \\ 1.35*2\frac{2}{9} =1.35*\frac{20}{9} =\frac{1.35*20}{9} =3$